This disclosure is directed to an accessory which materially assists and expedites the construction of an offshore platform. An offshore platform is defined for purposes of this disclosure as a permanent or semipermanent structure which is erected above the water surface at an offshore location. A permanent structure will utilize a superstructure above the water supported on a set of legs. Alternatively, it can be used with jackup drilling rigs which are portable, at least to the extent that they are moved from location to location between drilling jobs. Without regard to the manner of construction of the offshore platform, it avails itself of the present apparatus to enhance and expedite construction thereon. The construction which is referred to is not construction of the platform, itself; rather, it refers to construction of equipment on that platform. Typical equipment which is supported on the platform often includes pumps, valves, separators, a battery of storage tanks and the like. This type of equipment is normally found in a production platform. Alternatively, a fixed platform may be installed with drilling equipment on it, in which instance there will be a large number of mud tanks, mud pumps, a significant amount of superstructure and substructure for the drilling rig, itself, and other equipment.
The setting in which the present apparatus is used is one fraught with expensive hand labor in a dangerous environment. Typically, a platform will be formed at a shore location. Whether the platform is a permanent platform or a semisubmersible drilling rig, it is transported to a desired location at sea. The platform is then installed either temporarily or permanently. The platform so installed is normally installed with only the platform, but the operative equipment which is to be placed on it is normally attached only after the platform is made secure at sea. Thus, a large, fixed offshore platform will be assembled in parts (sometimes two or three major structural components) at a shore location, and the parts will thereafter be towed to sea for erection. At the time of erection, the platform is erected so that the deck is located significantly above the water and high above the wave action. At this time, the platform is actually devoid of drilling equipment or production equipment. It is merely a working surface for such equipment. The drilling equipment or production equipment, as the case may be, is thereafter installed on the platform. For instance, a barge supporting a crane will travel to the platform site, and, in conjunction with barge carried, fluid handling equipment, construction of the production or drilling equipment at the platform then occurs. Consider, as an easy example, well completion apparatus including a battery of tanks, a separator, valves and pumps. All of this equipment is carried by barge to the offshore platform. It is lifted by crane from the transportation barge to the platform. Thereafter, it must be plumbed by making suitable connections to the producing well and connections between the various components supported on the platform. A tremendous number of connections must be made. In many instances, the connections made are not permanent. They may be left intact for a few weeks or months and thereafter switched as the needs of the moment change. As an example, the platform may support both production equipment and drilling equipment. Later on, the drilling equipment may be removed and replaced with production equipment. Later on, the nature of the production may, itself, change, and new production equipment may be required. In every instance, it is necessary to disconnect and perhaps reconnect (via plumbing) the equipment at the platform.
The foregoing provides a setting or context in which the problem met by the present apparatus is assisted through the implementation of this apparatus. Thus, one advantage of the present invention is that it accommodates and expedites installation of equipment at the platform. As an example, if a tank battery is placed on the platform, it may be necessary to make a large number of connections through the platform floor, along the bottom side and back up through the floor to interconnect the various tanks in the tank battery. As this occurs, the platform is cut many times, and various and sundry hangers are connected on the bottom side to support the various pipes, valves and other equipment. Most of the plumbing is installed on the bottom side because the top surface is reserved for the equipment supported on the platform and at least a minimum area for workmen. Accordingly, the platform is perforated at many locations, and a great number of pipes will be hung from the bottom side. This occurs in a random manner, and, accordingly, the bottom side of the platform, after the platform has been replumbed two or three times, becomes a veritable forest of odd sizes and shapes of scaffoldings, miscellaneous hangers and the like. This makes working on the bottom side of the platform difficult to set up and difficult to conduct. All kinds of jerry-rigged scaffolding devices have been used heretofore.
From the foregoing, it will be observed that the bottom side of the platform becomes so littered with cut off pieces of scaffolding, old connectors, pipes no longer in use and operative plumbing and pipes that convenient access is almost impossible to obtain. The present invention overcomes this handicap in that it provides a system for rigging scaffolding beneath a plaform which leaves the platform intact after the scaffolding has been removed. Moreover, it can be installed quickly and easily without welding. One advantage is, therefore, the speed with which installation is made, and removal is implemented when desired. The scaffolding of this disclosure is advantageous over competitive types of scaffolding which have primarily been structures of convenience, typically tack welded to the bottom side of the platform at some location. The installation of temporary scaffolding heretofore has simply littered the bottom side of platforms so that accessibility is thereby limited after erection of scaffolding several times.
This disclosure sets forth an improved scaffolding system which is temporarily installed and subsequently removed without damaging or harming the platform structure. It has the advantage that it can be used incrementally; by that, reference is made to the fact that the scaffolding can be installed to provide a small or a very large work area. In the event a large work area beneath the platform is desired, this invention furnishes a scaffolding which is extended by merely repetitively utilizing the same apparatus to support a larger surface area. This carries with it the benefit of uniformity. The uniform structure enables rather rapid fabrication and disassembly.
A further advantage of the present apparatus is that its connection to the platform does not leave any debris in the form of welded plates scattered at random across the bottom side of the platform. After removal, the only thing remaining on the bottom side of the platform is the plumbing and other pipes which are installed beneath the platform with the equipment on it. However, the scaffolding, itself, is fully removed.
With these advantages and objects in mind, the present apparatus is briefly summarized as an accessory to be attached to the nether side of a platform at an offshore location. It utilizes hanger straps which are elongate straps terminating at a pair of facing hooks at the upper end which clamp to beams in the platform structure. They terminate at support plates which, in turn, hold up scaffolding beams, enabling construction of planking into decks of an extent determined by the number of hangers and beams installed in the scaffolding. It is installed by temporarily connecting the hanger straps to the platform. It is removed by disconnecting them. They connect and disconnect through manipulation of a pair of facing hooks.